Category: vaccination

Call for application for PhD studentship

STIRF has awarded a 3-year PhD studentship under the supervision of Professor Amanda J. Mason-Jones at the Department of Global Health, Department of Health Sciences, Faculty of Science, University of York, UK.

Subject:

“HPV vaccination for preventing cervical and other HPV-associated cancers: Comparing the knowledge and understanding of factors influencing initiation and completion of the UK and Ugandian school-based vaccination programme”.

Should children exposed to sexual abuse be offered human papillomavirus (HPV) vaccination alongside screening for sexually transmitted infections? A recent article in the Lancet argues for a yes answer.

The WHO defines childhood sexual abuse as the involvement in sexual activity of a child under the age of 18 years who did not give informed consent or is not developmentally prepared.

The global prevalence of childhood sexual abuse is estimated to be 8–31% for girls and 3–17% for boys. The true figures are probably nearer the upper figure.

According to a review, parents were the perpetrators of about 45% of cases of childhood sexual abuse in the USA, and other relatives were responsible for a further 19%. Others included figures of authority such as priests and teachers. Survivors of such abuse are often hesitant to report such incidents because of shame and fear of retribution. Thus, the incidence and prevalence of childhood sexual abuse is almost certainly underestimated.Read more

The incidence of high grade cervical lesions in young women in the United States has fallen, a new analysis has found. Susan Hariri and her colleagues reported in the journal Cancer that this may be caused by the introduction of the human papillomavirus (HPV) vaccine but may also be due to changes in screening guidelines.

From 2008 to 2012, 9119 cases of high grade cervical lesions (CIN2+) were reported among 18 to 39 year olds as part of a sentinel system for the US Centers for Disease Control and Prevention.

In all four catchment areas the researchers found a dramatic and consistent decrease in the incidence of high grade lesions among women aged 18 to 20 over the study period.

In California the incidence fell from 94 in 100 000 to 5 in 100 000

In Connecticut it fell from 450 to 57 in 100 000

In New York it fell from 299 to 43 in 100 000

In Oregon it fell from 202 to 37 in 100 000.

No change was seen among 30 to 39 year olds.

Vaccination against HPV has been available in the US since 2006. It is offered to girls aged 9 to 12 and as part of short term catch-up scheme targeting 13 to 26 year olds. The picture is unclear, however, as the recommended age for initiating cervical cancer screening was raised to 21 years during the same period, and screening intervals have been extended.

The study concluded that the declines in CIN2+ detection in young women were likely due to reduced screening but could also reflect the impact of vaccination.

In a recent editorial in the British Medical Journal (available only on subscription), Margaret Stanley and coauthors urged the UK government to introduce a gender neutral vaccination programme against HPV in schools for boys and girls aged 12-13 to reduce not only ano-genital warts but HPV-related cancers. These include cervical cancer in women, anal cancers in men who have sex with men and oropharyngeal cancers.

The authors point out that oropharyngeal cancers have the fastest rising incidence (15% per year) and anal cancer rates in the UK have risen by nearly 300% in the last 40 years..

HPV vaccination of young women with the quadrivalent vaccine (HPV4) resulted in a dramatic fall in genital warts and cervical cancer rates. However rolling out a similar vaccination in young men has been hampered by arguments that male HPV4 vaccination programmes exceed cost-effectiveness thresholds.

Unlike the USA and Australia, European countries do not include men in HPV vaccination programmes, instead focusing on achieving expanded coverage among women to promote herd immunity.

Yet there is evidence that HPV4 vaccination offers substantial clinical benefits to men and is cost effective among men who have sex with men (MSM). MSM have largely been excluded from mathematical models. A recent study in the journal Sexually Transmitted Infections has shown that HPV related conditions such as anal/genital warts and rectal infections are likely to be profoundly underdiagnosed among MSM in most European cities. The paper concluded that there is an urgent need to improve sexual healthcare tailored to MSM at risk for STIs.

There is also the argument for a gender-neutral (universal) approach to vaccination.

In the same issue of STI a meta-analysis shows that there are currently a number of obstacles to acceptability of HPV vaccination in men. They concluded that Public health campaigns should aim to promote positive HPV vaccine attitudes and awareness about HPV risk in men. The paper recommended interventions to promote HPV vaccination for boys and to overcome obstacles to HPV vaccine acceptability for men.

A recent editorial by Simon Barton and Colm O’Mahony in the BMJ highlight real and large declines at the population level of genital warts in both sexes in areas where mass vaccination by the quadrivalent vaccine have been implemented. The authors summarise the achievements to date:

1. A study published by Hammad Ali et al in the same issue reports that survey of of 85 770 new patients from six Australian sexual health clinics show a remarkable reduction in the proportion of women under 21 years of age presenting with genital warts—from 11.5% in 2007 to 0.85% in 2011 (P<0.001). Only 13 cases of genital warts were diagnosed in women under the age of 21 across all six health clinics in 2011. There was no observable effect in women over 30.

2. Interestingly, even though only young women were offered vaccination, there was also a significant decline in genital warts in young men. Between 2007 and 2011 there was a decline of 82% in the prevalence of warts presenting to sexual health clinics in heterosexual men under 21 and 51% in heterosexual men aged 21-30. There were no observed change in prevalence of genital warts in men who have sex with men (MSM). This decline of genital warts in young heterosexual men was thought to be caused to increased herd immunity.

3. Based on these and similar findings and also on grounds of equity the Australian government has begun a publicly funded HPV vaccination program for young men. This aims to reduce the prevalence of genital warts in MSM and also hopefully effect the rising rates of oropharyngeal cancers in men. Ali et al commented that “the vaccination program is expected to increase herd immunity and provide further indirect protection to unvaccinated women” hopefully leading to control, if not elimination of teh targeted HPV types.

4. It is believed that similar falls in HPV-16 and HPV-18 related cancers – such as cervical, anal and oripharyngeal cancers will be reported in the next few years.

5. The editorial expressed the hope that future vaccines will include other potentially harmful HPV types, such as types 31 and 45.

The Lancet has devoted an entire issue to various aspects of global health. The issue is available free for download.

An edited extract from the executive summary follows:

The Global Burden of Disease Study 2010 (GBD 2010) is the largest ever systematic effort to describe the global distribution and causes of a wide array of major diseases, injuries, and health risk factors.

The results show that infectious diseases, maternal and child illness, and malnutrition now cause fewer deaths and less illness than they did twenty years ago. As a result, fewer children are dying every year, but more young and middle-aged adults are dying and suffering from disease and injury.

Thus non-communicable diseases, such as cancer and heart disease, become the dominant causes of death and disability worldwide.

Since 1970, men and women worldwide have gained slightly more than ten years of life expectancy overall, but they spend more years living with injury and illness.

Since US public health officials began recommending in 2006 that young women be routinely vaccinated against HPV, many parents have hesitated over fears that doing so might give their children license to have sex. Research published on Monday in the journal Pediatrics and reported in the New York Times of October 15 may help ease those fears.

Using a sample of nearly 1,400 girls, the researchers found no evidence that those who were vaccinated beginning around age 11 went on to engage in more sexual activity than girls who were not vaccinated.

“We’re hopeful that once physicians see this, it will give them evidence that they can give to parents,” said Robert A. Bednarczyk, the lead author of the report and a clinical investigator with the Kaiser Permanente Center for Health Research Southeast, in Atlanta. “Hopefully when parents see this, it’ll be reassuring to them and we can start to overcome this barrier.”

HPV, the most common sexually transmitted virus in the United States, can cause cancers of the cervix, anus and parts of the throat. Federal health officials began recommending in 2006 that girls be vaccinated as early as age 11 and last year made a similar recommendation for preadolescent boys. The idea is to immunize boys and girls before they become sexually active to maximize the vaccine’s protective effects.

Data from the CDC showed that in 2011 nearly a third of children 14 to 19 years old are already infected with HPV. But despite the federal recommendations, vaccination rates around the country remain low, in part because of concerns about side effects as well as fears the vaccine could make adolescents less wary of casual sex. A study by Basu et al from Yale on parental attitudes toward the vaccine found that concern about promiscuity was the single biggest factor in the decision not to vaccinate.

Although overall rates of sexually transmitted infections rose by 2%, there has been an increase of 25% in new infections by gonorrhoea reported to the UK Health Protection Agency (HPA) – the second increase in two years running. Gonorrhoea rates increased from 16,835 to 20,965.

Other significant increases in sexually transmitted infections were in infectious syphilis (10%; 2,650 to 2,915) and genital herpes (5%; 29,794 to 31,154).

In contrast there was only a 1% rise in genital warts, perhaps reflecting the effectiveness of the vaccination programme. Diagnoses of genital warts cases in women aged 15-19 actually fell by 14% (11,251 to 9,700).

The greatest increase in sexually transmitted infections was in men who have sex with men and in heterosexual men and women aged 15-24. The high rates of infection reported in girls aged 15-19 is particularly worrying.

According to Professor Cathy Ison, director of sexually transmitted bacterial reference laboratory, the appearance of resistant strains for which no single antibiotic is effective is particularly worrying. This opens the prospect of having to use combination therapy in the future.

Research on effective behavioural change therefore remains a top priority.